1. Field of the Invention
The present invention relates to a pedestrian detecting apparatus that precisely detects a pedestrian.
2. Description of the Related Art
In recent years, various environment recognizing and sensing technologies have been developed for applications to vehicle drive assist systems. Above all, detection of pedestrians has attracted attention. A collision between a pedestrian and a vehicle is frequently caused by the delay of the driver in recognizing the pedestrian, and this collision heavily damages the pedestrian. Accordingly, it is necessary to detect the pedestrian as quickly and precisely as possible.
For example, Japanese Unexamined Patent Application Publication No. 2004-298285 discloses a technique of detecting the walking condition of a pedestrian. In this technique, the top of the head of a pedestrian is detected in a two-dimensional image, and a trajectory of the top of the head on the time axis is obtained from a temporal transition of the position of the top in the image. By subjecting the trajectory to frequency analysis, a frequency spectrum of the motion of the top of the head is obtained. On the basis of the frequency spectrum, a fundamental frequency of the walking motion is specified and compared with a predetermined walking condition model, thus detecting the walking condition of the pedestrian.
Unfortunately, in the technique of detecting the condition of the pedestrian or detecting the pedestrian by comparison with the prestored model, as disclosed in the above-described publication, it is necessary to learn more models beforehand in order to improve the detection accuracy. Moreover, the amount of data to be processed for detection increases, and this leads to detection delay.